1. Field of the Invention
The present invention relates to a device and a method for controlling transmission power in a mobile terminal. More particularly, the present invention relates to a device and a method for satisfying a Specific Absorption Rate (SAR) standard by controlling transmission power depending on a distance between a mobile terminal and a user.
2. Description of the Related Art
Generally, a mobile terminal is used in such a manner that the mobile terminal is disposed adjacent to a user's head between the user's ear and mouth. In this case, the electromagnetic wave generated in the mobile terminal during a call may affect the health of the user. Therefore, every country designs a Specific Absorption Rate (SAR) standard to define the permissible amount of electromagnetic energy the mobile terminal may generate. The SAR standard for the bands of each region is different. For example, in a case of European bands (e.g., GSM900, DCS, W900, W2100), the SAR standard is 2.0 W/kg (10 g average). Whereas, in a case of Central and South American bands (e.g., GSM850, PCS, W850, W1900), the SAR standard is 1.6 W/KG (1 g average), which is a more stringent SAR standard. A method for controlling the performance of an antenna is used in the related art to satisfy the SAR standard. In this case, the performance of the antenna is unable to be optimized so that the SAR International standard may be satisfied (i.e., avoid a failure or margin shortfall) even when the performance of the antenna in free space can be sufficiently enhanced. For example, in a case where the mobile terminal is being brought to a global market, it might be necessary to lower the performance of the antenna of the mobile terminal so as to satisfy (i.e., avoid a failure or margin shortfall) the SAR standard in the Central and South American bands where the SAR standard is more stringent than the European bands. This is more likely the case when a mobile terminal for Central and South America is developed after completing the development of the optimized performance of the antenna for Europe. Hence, in the mobile terminal of the related art, the performance of the antenna cannot be optimized so that the SAR International standard is satisfied, even when the performance of the antenna in free space can be sufficiently enhanced. Accordingly, the performance of an antenna is lowered to the free space transmission and reception rate. In order to address such a problem, when antennas corresponding to respective mobile terminals (i.e., a mobile terminal for Europe and a mobile terminal for Central and South America) using a different SAR standard are used, there is a delay in the development of an antenna and an increase in costs such as a maintenance cost and an inventory cost.